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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Nuclear Data Sheets for A = 70

Spectroscopic data for all nuclei with mass number A = 70 have been evaluated, and the corresponding level schemes from radioactive decay and reaction studies are presented. Since the previous evaluation, the half-life of {sup 70}Mn has been measured and excited states in {sup 70}Fe observed for the first time. Excited states in {sup 70}Ni have been more extensively studied while Coulomb excitation and collinear laser spectroscopy measurements in {sup 70}Cu have allowed for firm Jπ assignments. Despite new measurements, there remain some discrepancies in half-lives of low lying states in {sup 70}Zn. New measurements have extended the knowledge of high-spin band structures in {sup 70}Ge and {sup 70}As. This evaluation supersedes the prior A = 70 evaluation of 2004Tu09.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

Anaerobic reductive bioleaching of manganese ores

The increasing demand of manganese in the industries and various hindrances in its production from low grade ores by conventional method has made it imperative for researchers around the world to develop a method of manganese extraction from low grade ores that is both environment-friendly and economical. Bioleaching has shown significant potential in manganese extraction and efficiencies of extraction have been found to be 70–98% with the help of various bacteria and fungi. Here, this study focuses on extraction of manganese with the help of mixed bacterial strains that have been collected from their natural anaerobic environment where manganese reducing activity was evident. The extraction of manganese from reagent grade manganese dioxide and high grade manganese ore has been studied over 180 days in an anaerobic environment at room temperature and pH around 5, without the addition of any mineral acids. Highest concentrations of dissolved manganese have been found to be 928.58 mg Mn/L for reagent grade manganese dioxide and 864.54 mg Mn/L for ore grade manganese, corresponding to 650 mg and 400 mg of cumulative manganese, respectively.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

High Z permanent magnets for radiation shielding

A magnetic shielding material includes a material comprising manganese bismuth (MnBi) and tungsten (W), where a ratio of MnBi:W is in a range of 50:50 to about 70:30. A radiation shielding product includes a part including manganese bismuth (MnBi) and tungsten (W), and a plurality of layers having a defined thickness in a z-direction, wherein each layer extends along an x-y plane perpendicular to the z-direction. At least some of the plurality of layers form a functional gradient in the z-direction and/or along the x-y plane, and the functional gradient is defined by a first layer comprising a ratio of MnBi:W being less than 100:0 and an nth layer above the first layer comprising a ratio of MnBi:W greater than 0:100.

McCall, Scott↗
DOE OSTI2016

Immunotoxicological and neurotoxicological profile of health effects following subacute exposure to geogenic dust from sand dunes at the Nellis Dunes Recreation Area, Las Vegas, NV

Exposure to geogenic particulate matter (PM) comprised of mineral particles has been linked to human health effects. However, very little data exist on health effects associated with geogenic dust exposure in natural settings. Therefore, we characterized particulate matter size, metal chemistry, and health effects of dust collected from the Nellis Dunes Recreation Area (NDRA), a popular off-road vehicle area located near Las Vegas, NV. Adult female B6C3F1 mice were exposed to several concentrations of mineral dust collected from active and vegetated sand dunes in NDRA. Dust samples (median diameter: 4.4 μm) were suspended in phosphate-buffered saline and delivered at concentrations ranging from 0.01 to 100 mg dust/kg body weight by oropharyngeal aspiration. ICP-MS analyses of total dissolution of the dust resulted in aluminum (55,090 μg/g), vanadium (70 μg/g), chromium (33 μg/g), manganese (511 μg/g), iron (21,600 μg/g), cobalt (9.4 μg/g), copper (69 μg/g), zinc (79 μg/g), arsenic (62 μg/g), strontium (620 μg/g), cesium (13 μg/g), lead 25 μg/g) and uranium (4.7 μg/g). Arsenic was present only as As(V). Mice received four exposures, once/week over 28-days to mimic a month of weekend exposures. Descriptive and functional assays to assess immunotoxicity and neurotoxicity were performed 24 h after the final exposure. The primary observation was that 0.1 to 100 mg/kg of this sand dune derived dust dose-responsively reduced antigen-specific IgM antibody responses, suggesting that dust from this area of NDRA may present a potential health risk. - Graphical abstract: During periods of heavy wind erosion, dense dust clouds of locally emitted geogenic dust enrobe the central Nellis Dune Recreation Area dunes. - Highlights: • Toxicological effects were characterized specific to geogenic dust exposure from a recreational sand dune site in Nevada. • The geogenic dust is a mixture of many metals and crystalline silica. • Exposure to geogenic dust dose-responsively decreased IgM antibody responses in a mouse model.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Thermally initiated disproportionation of manganese(II) bis(1-hydroxyethylidene)diphosphonate. Formation and properties of the lepidoid structure of manganese(II) (1-hydroxyethylidene)diphosphonate-2-hydroxyethaneaminium whiskers. Agronomical efficiency of the manganese(II) complex with (1-hydroxyethylidene)diphosphonic acid

The reaction of poorly soluble manganese(II) bis(1-hydroxyethylidene)diphosphonate tetrahydrate (Mn(H{sub 3}L){sub 2}•4H{sub 2}O) with 2-aminoethanol (H{sub 2}NCH{sub 2}CH{sub 2}OH) in an aqueous medium on heating to 70—80 оС causes the initial formation of soluble manganese(II) bis(1-hydroxyethylidene)diphosphonate tris(1-hydroxyethaneaminium) (Mn(H{sub 3}L)2• •3H{sub 2}NCH{sub 2}CH{sub 2}OH•4H{sub 2}O), which then disproportionates to slightly soluble manganese(II) (1-hydroxyethylidene)diphosphonate-2-hydroxyethaneaminium (MnH{sub 2}L•H{sub 2}NCH{sub 2}CH{sub 2}OH) and coordination polymer of 1-hydroxyethylidenediphosphonic acid with 2-aminoethanol containing no metal cations. In the course of the reaction, MnH{sub 2}L•H{sub 2}NCH{sub 2}CH{sub 2}OH precipitates as whiskers that are grouped into a leaf (lepidoid) structure. The latter was examined by IR spectroscopy, X-ray phase analysis, scanning electron microscopy, atomic force microscopy, optical microscopy, and thermal desorption of nitrogen. The starting and resulting manganese compounds refer to poorly soluble crystalline complexes. The presence of a 2-aminoethanol molecule in the final product leads to an increase in the solubility from 0.40 to 0.54 g in 100 mL of the solution. Poorly soluble MnH{sub 2}L•H{sub 2}NCH{sub 2}CH{sub 2}OH is easily converted to a soluble form by the treatment with 2-aminoethanol or 2-amino-2-(hydroxy- methyl)propane-1,3-diol (H{sub 2}NC(CH{sub 2}OH)3). The agronomical efficiency of a solution of the Mn(H{sub 3}L){sub 2}•3H{sub 2}NCH{sub 2}CH{sub 2}OH•4H{sub 2}O complex was studied on the cultures of white lupine Degas, spring wheat Ester, spring rape, and pea Stabil.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Solubility Testing to Support the Addition of Sodium Reactor Experiment Material to Sludge Batch 10

The Savannah River Site H-Canyon Facility is planning to discard dissolved Sodium Reactor Experiment (SRE) material into Tank 51 prior to Sludge Batch 10 (SB10). SB10 with the SRE material will be processed in the Defense Waste Processing Facility (DWPF) using the Nitric-Glycolic Acid (NGA) flowsheet. The DWPF Nuclear Criticality Safety Evaluation (NCSE) protects a 14:1 mass ratio of manganese to equivalent uranium-235 in both the solid and liquid phases during processing by requiring a 70:1 mass ratio in the feed. A concern was raised that freshly precipitated manganese in the SRE material will behave differently from the manganese in sludge during DWPF processing and potentially invalidate the criticality control. To mitigate risks to the DWPF criticality controls, the Savannah River National Laboratory (SRNL) performed a metals solubility test applicable to recently precipitated manganese and uranium, as would be expected with SRE transfers to SB10. The objective of this analysis is the tracking of partitioning of the primary fissile component (uranium-235) with the credited poison (manganese) between the aqueous and insoluble phases.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2013

BD-22deg3467, a DAO-type Star Exciting the Nebula Abell 35

Spectral analyses of hot, compact stars with non-local thermodynamical equilibrium (NLTE) model-atmosphere techniques allow the precise determination of photospheric parameters such as the effective temperature (T(sub eff)), the surface gravity (log g), and the chemical composition. The derived photospheric metal abundances are crucial constraints for stellar evolutionary theory. Aims. Previous spectral analyses of the exciting star of the nebula A35, BD-22deg3467, were based on He+C+N+O+Si+Fe models only. For our analysis, we use state-of-the-art fully metal-line blanketed NLTE model atmospheres that consider opacities of 23 elements from hydrogen to nickel. We aim to identify all observed lines in the ultraviolet (UV) spectrum of BD-22deg3467 and to determine the abundances of the respective species precisely. Methods. For the analysis of high-resolution and high signal-to-noise ratio (S/N) far-ultraviolet (FUSE) and UV (HST/STIS) observations, we combined stellar-atmosphere models and interstellar line-absorption models to fully reproduce the entire observed UV spectrum. Results. The best agreement with the UV observation of BD-22deg3467 is achieved at T(sub eff) = 80 +/- 10 kK and log g = 7.2 +/- 0.3. While T(sub eff) of previous analyses is verified, log g is significantly lower. We re-analyzed lines of silicon and iron (1/100 and about solar abundances, respectively) and for the first time in this star identified argon, chromium, manganese, cobalt, and nickel and determined abundances of 12, 70, 35, 150, and 5 times solar, respectively. Our results partially agree with predictions of diffusion models for DA-type white dwarfs. A combination of photospheric and interstellar line-absorption models reproduces more than 90% of the observed absorption features. The stellar mass is M approx. 0.48 Solar Mass. Conclusions. BD.22.3467 may not have been massive enough to ascend the asymptotic giant branch and may have evolved directly from the extended horizontal branch to the white dwarf state. This would explain why it is not surrounded by a planetary nebula. However, the star, ionizes the ambient interstellar matter, mimicking a planetary nebula.

Ziegler, M.↗
DOE OSTI2015

Synthesis of manganese stearate for high density polyethylene (HDPE) and its biodegradation

An oxidant additive is one type of additive used for oxo-biodegradable polymers. This additive was prepared by reaction multivalent transition metals and fatty acids to accelerate the degradation process of polymers by providing a thermal treatment or irradiation with light. This study focused on the synthesis of manganese stearate as an additive for application in High Density Polyethylene (HDPE), and the influence of manganese stearate on the characteristics of HDPE including their biodegradability. Manganese stearate was synthesized by the reaction of stearic acid with sodium hydroxide, and sodium stearate formed was reacted with manganese chloride tetrahydrate to form manganese stearate with a melting point of 100-110 °C. Based on the FTIR spectrum showed absorption peak at wave number around 1560 cm{sup −1} which is an asymmetric vibration of CO functional group that binds to the manganese. The films of oxo-biodegradable polymer were prepared by blending HDPE and manganese stearate additives at various concentrations with using the polymer melting method, followed heating at a temperature of 50°C and 70°C for 10 days. The characterizations of the oxo-biodegradable polymers were carried out by analysis the functional groups (FTIR and ATR),thermal properties (TGA), surface properties (SEM), as well as analysis of the biodegradability (the biodegradation test by using activated sludge, % weight loss). Based on COi indicate that the additive of manganese stearate is active in oxidizing polymer by heating treatment. Results of biodegradation by microorganisms from activated sludge showed that the percentage weight loss of polymers increase with the increasing incubation time and the concentration of manganese stearate in HDPE. Biodegradability of HDPE with the addition of manganese stearate and followed by heating at a higher temperature was better observed. The highest percentage weight loss was obtained at the polymer with concentration of 0.2% manganese stearate, and followed by thermal treatment at a temperature of 70 °C and the incubation time for 45 days in the activated sludge.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2013

Small plasma focus as neutron pulsed source for nuclides identification

In this paper, we present preliminary results on the feasibility of employing a low energy (2 kJ, 31 kV) plasma focus device as a portable source of pulsed neutron beams (2.45 MeV) generated by nuclear fusion reactions D-D, for the “in situ” analysis of substances by nuclear activation. This source has the relevant advantage of being pulsed at requirement, transportable, not permanently radioactive, without radioactive waste, cheap, among others. We prove the feasibility of using this source showing several spectra of the characteristic emission line for manganese, gold, lead, and silver.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2019

Quantum Corrections and Magnetotransport in 3D Dirac Semimetal Cd{sub 3 –x}Mn{sub x}As{sub 2} Films

Thin films of solid solutions based on the three-dimensional Dirac semimetal Cd{sub 3}As{sub 2} with the addition of manganese are investigated. Cd{sub 3 –x}Mn{sub x}As{sub 2} films (x = 0, 0.05, and 0.1) 50–70 nm in thickness are formed on a glassceramic substrate using vacuum-thermal deposition from cadmium arsenide ingots doped by Mn and fabricated by direct alloying elements by the vacuum-cell method. The temperature and magnetic-field dependences of the resistance are measured and the transport parameters of the films under study are determined. Positive magnetoresistance of the characteristic shape corresponding to the contribution of the weak antilocalization effect is observed for films with x = 0 and 0.05. The contribution from the weak localization effect is observed at a higher Mn content (x = 0.1). This change in the quantum correction type as applied to topological semimetals points to reconstruction of the band structure and transition from the Dirac semimetal state into a trivial semiconductor phase, which corresponds to the critical Mn content x{sub c} ~ 0.07 in this case.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2022

Super-hydration and reduction of manganese oxide minerals at shallow terrestrial depths

Manganese oxides are ubiquitous marine minerals which are redox sensitive. As major components of manganese nodules found on the ocean floor, birnessite and buserite have been known to be two distinct water-containing minerals with manganese octahedral interlayer separations of ~7 Å and ~10 Å, respectively. We show here that buserite is a super-hydrated birnessite formed near 5 km depth conditions. As one of the most hydrous minerals containing ca. 34.5 wt. % water, super-hydrated birnessite, i.e., buserite, remains stable up to ca. 70 km depth conditions, where it transforms into manganite by releasing ca. 24.3 wt. % water. Subsequent transformations to hausmannite and pyrochroite occur near 100 km and 120 km depths, respectively, concomitant with a progressive reduction of Mn 4+ to Mn 2+ . Our work forwards an abiotic geochemical cycle of manganese minerals in subduction and/or other aqueous terrestrial environments, with implications for water storage and cycling, and the redox capacity of the region.

36 MATERIALS SCIENCE↗
NASA NTRS1977

The effect of temperature and pressure on the distribution of iron group elements between metal and olivine phases in the process of differentiation of protoplanetary material

The distribution patterns of Ni, Co, Mn, and Cr were studied in olivines of various origins: from meteorites (chondrites, achondrites, pallasites), which are likely analogs of the protoplanetary material, to peridotite inclusions in kimberlite pipes, which are analogs of mantle material. According to X-ray microanalysis data, nickel is concentrated in peridotite olivines, while manganese is concentrated in meteoritic olivines. The maximum chromium content was found in ureilites, which were formed under reducing conditions. Experiments at pressures of 20 to 70 kbar and temperatures of 1100 to 2000 C have shown that in a mixture of olivine and Ni metal or NiO, nickel enters the silicate phase, displacing Fe into the metallic phase. Equilibrium temperatures were estimated from the Fe, Ni distribution coefficients between the metal and olivine: 1500 K for pallasites, 1600 K for olivine-bronzite H6 chondrites, 1200 K for olivine-hypersthene L6, 900 K for LL6, and 1900 K for ureilites (at P = 1 atm). The equilibrium conditions of peridotites are close to T = 1800 K and P over 100 kbar. It is concluded that there is a sharp difference between the conditions of differentiation of the protoplanetary material at the time meteorites were formed and the conditions of differentiation of the planets into concentric layers.

Vinogradov, A. P.↗
DOE OSTI2015

Modification of modulated plasma plumes for the quasi-phase-matching of high-order harmonics in different spectral ranges

We demonstrate the technique allowing the fine tuning of the distance between the laser-produced plasma plumes on the surfaces of different materials, as well as the variation of the sizes of these plumes. The modification of plasma formations is based on the tilting of the multi-slit mask placed between the heating laser beam and target surface, as well as the positioning of this mask in the telescope placed on the path of heating radiation. The modulated plasma plumes with the sizes of single plume ranging between 0.1 and 1 mm were produced on the manganese and silver targets. Modification of the geometrical parameters of plasma plumes proved to be useful for the fine tuning of the quasi-phase-matched high-order harmonics generated in such structures during propagation of the ultrashort laser pulses. We show the enhancement of some groups of harmonics along the plateau range and the tuning of maximally enhanced harmonic by variable modulation of the plasma.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2014

Low- and high-order harmonic generation in the extended plasmas produced by laser ablation of zinc and manganese targets

The systematic studies of the harmonic generation of ultrashort laser pulses in the 5-mm-long Zn and Mn plasmas (i.e., application of nanosecond, picosecond, and femtosecond pulses for ablation, comparison of harmonic generation from atomic, ionic, and cluster-contained species of plasma, variation of plasma length, two-color pump of plasmas, etc.) are presented. The conversion efficiency of the 11th–19th harmonics generated in the Zn plasma was ∼5 × 10{sup −5}. The role of the ionic resonances of Zn near the 9th and 10th harmonics on the enhancement of harmonics is discussed. The enhancement of harmonics was also analyzed using the two-color pump of extended plasmas, which showed similar intensities of the odd and even harmonics along the whole range of generation. The harmonics up to the 107th order were demonstrated in the case of manganese plasma. The comparison of harmonic generation in the 5-mm-long and commonly used short (≤0.5 mm) plasma plumes showed the advanced properties of extended media.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2011

Time-resolved spectroscopy of plasma plumes: A versatile approach for optimization of high-order harmonic generation in laser plasma

The time-resolved studies of laser-produced Ag, In, Pt, V, Mn, and Ga plasmas are presented from the point of view of plasma application as the nonlinear optical medium for high-order harmonic generation of laser radiation. We show that optimization of plasma formation using this technique allows the enhancement of harmonic generation efficiency and extension of maximal harmonic order.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2017

Experimental study of antiferromagnetic resonance in noncollinear antiferromagnetic Mn{sub 3}Al{sub 2}Ge{sub 3}O{sub 12}

We have measured antiferromagnetic resonance (AFMR) frequency-field dependences for aluminum–manganese garnet Mn{sub 3}Al{sub 2}Ge{sub 3}O{sub 12} at frequencies from 1 to 125 GHz and fields up to 6 T. There are three AFMR modes for all orientations, their zero field gaps are about 40 and 70 GHz. Andreev–Marchenko hydrodynamic theory [7] well describes experimental frequency–field dependences. We have observed hysteresis of resonance absorption as well as history dependence of resonance absorption near gap frequencies below 10 kOe in all three measured field orientations, which are supposedly due to the sample domain structure. Observation of the AFMR signal at the frequencies from 1 to 5 GHz allows to estimate repulsion of nuclear and electron modes of spin precession in the vicinity of spin-reorientation transition at H || [100].

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2017

Design of template-stabilized active and earth-abundant oxygen evolution catalysts in acid

Oxygen evolution reaction (OER) catalysts that are earth-abundant and are active and stable in acid are unknown. Active catalysts derived from Co and Ni oxides dissolve at low pH, whereas acid stable systems such as Mn oxides (MnO x ) display poor OER activity. We now demonstrate a rational approach for the design of earth-abundant catalysts that are stable and active in acid by treating activity and stability as decoupled elements of mixed metal oxides. Manganese serves as a stabilizing structural element for catalytically active Co centers in CoMnO x films. In acidic solutions (pH 2.5), CoMnO x exhibits the OER activity of electrodeposited Co oxide (CoO x ) with a Tafel slope of 70–80 mV per decade while also retaining the long-term acid stability of MnO x films for OER at 0.1 mA cm -2 . Driving OER at greater current densities in this system is not viable because at high anodic potentials, Mn oxides convert to and dissolve as permanganate. However, by exploiting the decoupled design of the catalyst, the stabilizing structural element may be optimized independently of the Co active sites. By screening potential–pH diagrams, we replaced Mn with Pb to prepare CoFePbO x films that maintained the high OER activity of CoO x at pH 2.5 while exhibiting long-term acid stability at higher current densities (at 1 mA cm -2 for over 50 h at pH 2.0). Under these acidic conditions, CoFePbO x exhibits OER activity that approaches noble metal oxides, thus establishing the viability of decoupling functionality in mixed metal catalysts for designing active, acid-stable, and earth-abundant OER catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2013

Ferromagnetic (Ga,Mn)As nanowires grown by Mn-assisted molecular beam epitaxy

(Ga,Mn)As nanowires were grown by molecular beam epitaxy using Mn as a growth catalyst on GaAs(001) substrates at 485 Degree-Sign C, i.e., at intermediate temperatures higher than ones used for the growth of (Ga,Mn)As thin films, but lower than the ordinary temperatures of Au-assisted growth of GaAs nanowires. (Ga,Mn)As nanowires obtained with typical lengths between 0.8 and 4 {mu}m and diameters 50-90 nm do not have defects, such as dislocations or precipitates, except for the stacking faults lying parallel to the growth direction. The investigation of magnetic and optical properties has been carried out not only for as-grown samples with nanowires but also for peeled off nanowires from the host substrate. The results obtained demonstrate that (Ga,Mn)As nanowires exhibit ferromagnetic ordering around 70 K.

36 MATERIALS SCIENCE↗